diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/sx8.c | 50 |
1 files changed, 37 insertions, 13 deletions
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c index d57007b92f7..b5f612679a3 100644 --- a/drivers/block/sx8.c +++ b/drivers/block/sx8.c @@ -1,7 +1,7 @@ /* * sx8.c: Driver for Promise SATA SX8 looks-like-I2O hardware * - * Copyright 2004 Red Hat, Inc. + * Copyright 2004-2005 Red Hat, Inc. * * Author/maintainer: Jeff Garzik <jgarzik@pobox.com> * @@ -31,10 +31,6 @@ #include <asm/semaphore.h> #include <asm/uaccess.h> -MODULE_AUTHOR("Jeff Garzik"); -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("Promise SATA SX8 block driver"); - #if 0 #define CARM_DEBUG #define CARM_VERBOSE_DEBUG @@ -45,9 +41,35 @@ MODULE_DESCRIPTION("Promise SATA SX8 block driver"); #undef CARM_NDEBUG #define DRV_NAME "sx8" -#define DRV_VERSION "0.8" +#define DRV_VERSION "1.0" #define PFX DRV_NAME ": " +MODULE_AUTHOR("Jeff Garzik"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Promise SATA SX8 block driver"); +MODULE_VERSION(DRV_VERSION); + +/* + * SX8 hardware has a single message queue for all ATA ports. + * When this driver was written, the hardware (firmware?) would + * corrupt data eventually, if more than one request was outstanding. + * As one can imagine, having 8 ports bottlenecking on a single + * command hurts performance. + * + * Based on user reports, later versions of the hardware (firmware?) + * seem to be able to survive with more than one command queued. + * + * Therefore, we default to the safe option -- 1 command -- but + * allow the user to increase this. + * + * SX8 should be able to support up to ~60 queued commands (CARM_MAX_REQ), + * but problems seem to occur when you exceed ~30, even on newer hardware. + */ +static int max_queue = 1; +module_param(max_queue, int, 0444); +MODULE_PARM_DESC(max_queue, "Maximum number of queued commands. (min==1, max==30, safe==1)"); + + #define NEXT_RESP(idx) ((idx + 1) % RMSG_Q_LEN) /* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */ @@ -90,12 +112,10 @@ enum { /* command message queue limits */ CARM_MAX_REQ = 64, /* max command msgs per host */ - CARM_MAX_Q = 1, /* one command at a time */ CARM_MSG_LOW_WATER = (CARM_MAX_REQ / 4), /* refill mark */ /* S/G limits, host-wide and per-request */ CARM_MAX_REQ_SG = 32, /* max s/g entries per request */ - CARM_SG_BOUNDARY = 0xffffUL, /* s/g segment boundary */ CARM_MAX_HOST_SG = 600, /* max s/g entries per host */ CARM_SG_LOW_WATER = (CARM_MAX_HOST_SG / 4), /* re-fill mark */ @@ -181,6 +201,10 @@ enum { FL_DYN_MAJOR = (1 << 17), }; +enum { + CARM_SG_BOUNDARY = 0xffffUL, /* s/g segment boundary */ +}; + enum scatter_gather_types { SGT_32BIT = 0, SGT_64BIT = 1, @@ -448,7 +472,7 @@ static inline int carm_lookup_bucket(u32 msg_size) for (i = 0; i < ARRAY_SIZE(msg_sizes); i++) if (msg_size <= msg_sizes[i]) return i; - + return -ENOENT; } @@ -509,7 +533,7 @@ static struct carm_request *carm_get_request(struct carm_host *host) if (host->hw_sg_used >= (CARM_MAX_HOST_SG - CARM_MAX_REQ_SG)) return NULL; - for (i = 0; i < CARM_MAX_Q; i++) + for (i = 0; i < max_queue; i++) if ((host->msg_alloc & (1ULL << i)) == 0) { struct carm_request *crq = &host->req[i]; crq->port = NULL; @@ -521,14 +545,14 @@ static struct carm_request *carm_get_request(struct carm_host *host) assert(host->n_msgs <= CARM_MAX_REQ); return crq; } - + DPRINTK("no request available, returning NULL\n"); return NULL; } static int carm_put_request(struct carm_host *host, struct carm_request *crq) { - assert(crq->tag < CARM_MAX_Q); + assert(crq->tag < max_queue); if (unlikely((host->msg_alloc & (1ULL << crq->tag)) == 0)) return -EINVAL; /* tried to clear a tag that was not active */ @@ -791,7 +815,7 @@ static inline void carm_end_rq(struct carm_host *host, struct carm_request *crq, int is_ok) { carm_end_request_queued(host, crq, is_ok); - if (CARM_MAX_Q == 1) + if (max_queue == 1) carm_round_robin(host); else if ((host->n_msgs <= CARM_MSG_LOW_WATER) && (host->hw_sg_used <= CARM_SG_LOW_WATER)) { |